In a large flame proof casserole, melt the butter in the oil over moderate heat.,Dredge the veal in the flour and shake off any excess. Working in batches, saute veal on all sides until golden brown. Do not crowd the pan. Remove to a bowl.,Add the onions, carrots, celery and garlic. Cover and cook until vegetables are tender, about 15 minutes.,Place the veal on top of the vegetables, making sure the bones are upright. Sprinkle the marjoram, basil and thyme on top. Add the tomatoes, tomato paste, white wine, chicken stock, strips of lemon zest, bay leaf and parsley sprigs. If necessary, add enough water to cover the shanks.,Bring to a boil, reduce heat to low and simmer, covered, until the meat is tender, about 2 hours.,Transfer the veal shanks to a heated platter, remove the strings and cover with foil to keep warm. Increase the heat to high and boil, stirring frequently until the sauce is reduced by half, about 20 minutes. Pour the sauce over the meat.,______